kvm: vmx: Basic APIC virtualization controls have three settings

Previously, we toggled between SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE
and SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES, depending on whether or
not the EXTD bit was set in MSR_IA32_APICBASE. However, if the local
APIC is disabled, we should not set either of these APIC
virtualization control bits.

Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index b74c9c1..776391c 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1990,13 +1990,11 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
 		}
 	}
 
-	if ((old_value ^ value) & X2APIC_ENABLE) {
-		if (value & X2APIC_ENABLE) {
-			kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id);
-			kvm_x86_ops->set_virtual_x2apic_mode(vcpu, true);
-		} else
-			kvm_x86_ops->set_virtual_x2apic_mode(vcpu, false);
-	}
+	if (((old_value ^ value) & X2APIC_ENABLE) && (value & X2APIC_ENABLE))
+		kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id);
+
+	if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE))
+		kvm_x86_ops->set_virtual_apic_mode(vcpu);
 
 	apic->base_address = apic->vcpu->arch.apic_base &
 			     MSR_IA32_APICBASE_BASE;